This 2021 study investigated effects of light on red cabbage sprouts and microgreens. I’ll highlight its 3-day-old sprout findings:

“Periodic ultraviolet UV-B (280–320 nm) pulses at low doses improved morphological development of red cabbage sprouts, and probably will have the same effect on other sprouts. Similarly, total phenolic content, total flavonoid content, and total antioxidant capacity presented a UV-B dose-dependence response.

Although UV-B radiation may cause damage to plant tissues, an optimum dose can promote accumulation of antioxidant and UV-protective molecules that enhance nutraceutical biosynthesis in plant foods without altering sensory quality. Such an increase in concentration of bioactive compounds is mainly due to environmental stress generated by UV-B light, which leads to changes in morphology, physiology, and molecular conformation of DNA, RNA, and proteins.

Total phenolic content of control (0, CTRL) or UV-B-treated (5, 10, and 15 kJ m⁻²) red cabbage sprouts after 10 days growth at 20 °C. Different capital letters indicate significant differences among treatments at < 0.05. Different lowercase letters indicate significant differences among time of analysis of the same treatment at p < 0.05.

Our results demonstrated that application of UV-B light during germination induces a positive effect on growth of red cabbage sprouts, as well as on secondary metabolite content related to nutritional quality. Analysed bioactive compounds (phenolics, flavonoids, and carotenoids) increased during germination, and tended to remain constant throughout a refrigerated shelf life.”

https://www.mdpi.com/2311-7524/7/12/567/htm “UV-B Radiation as Abiotic Elicitor to Enhance Phytochemicals and Development of Red Cabbage Sprouts”

I came across this study after lead author Dr. Lorena Martínez-Zamora provided an earlier study, Postharvest UV-B and UV-C radiation enhanced the biosynthesis of glucosinolates and isothiocyanates in Brassicaceae sprouts (not freely available). Its focus was also a worthwhile commercialization of cruciferous microgreens.

Nearby researchers also published studies such as Red cabbage effects on gut microbiota and Sprout bioaccessibility last year. Let’s hope a push for cruciferous sprouts and microgreens continues, although consumer acceptance is limited by products not being sweet.

I think these research efforts will succeed. Take a look at oat milk’s quick rise, for example. I had trouble getting delivery of Avena sativa seeds last month because oat milk producers bought up last year’s supplies and futures on this year’s crops.

For me, it’s been 98 weeks of spending at least 45 minutes a day growing 3-day-old broccoli, red cabbage, mustard, and oat sprouts at home. I’m satisfied with results, and won’t turn my kitchen into a laboratory to eke out extra effects with light and other elicitors.

Here’s a photo of this study’s sponsoring institution’s harbor from the latest of two visits:

I’d like to return whenever we individually stop being herded and recover our sanity.